This invention relates to engine drive transmission and throttle control apparatus and more particularly to an integrated throttle control and transmission shift control for marine engines and the like.
In marine propulsion systems, remote control mechanisms are generally provided to permit shifting of a gear transmission for the drive mechanism between neutral, forward and reverse from the forward portion of the boat and further permitting setting of the throttle for varying the engine speed. Single lever remote controls have been developed and interconnected to an integrated shift mechanism and throttle mechanism to permit control by pivotal movement of the single lever. Generally, the system provides for full forward or reverse gear engagement before the engine throttle mechanism is engaged. To permit warm-up and the like, various mechanisms have also been suggested to permit advancing of the throttle in the neutral drive position with the shift mechanism disengaged. Generally, such systems employ cam coupling and drive for selectively engaging and disengaging of the several mechanisms. For example, U.S. Pat. No. 3,309,938 assigned to the assignee of the present application discloses a cam operated single lever control having means for disengaging of the shift mechanism in response to actuation of a warm-up button. As more fully disclosed therein, the mechanism is mounted for actuation around a common drive shaft mechanism. The elements are held in a neutral position by a suitable detent means. When the warm-up button is actuated, the lever coupling to the shift mechanism is disengaged such that the shift mechanism is held in the neutral position by the detent. Although this and similar disconnect means have been suggested, a simple, reliable and positive interlock is desired which absolutely positively prevents shifting of the mechanism either accidentally or through malfunctioning when the warm-up button has been actuated. Further the total mechanism must be maintained within a small, compact and aesthetically pleasing unit to permit practical adaptation to a commercial production.